The present invention relates generally to apparatus and methods for assembling injection devices, and more particularly to apparatus and methods for loading syringes into adapters or guard devices including shields for covering needles of the syringes after use.
Medication is often dispensed using a medical cartridge, such as a syringe, having a barrel with a needle extending from one end and a plunger slidably inserted into the other end. Such cartridges are often referred to as xe2x80x9cpre-filled syringesxe2x80x9d because they contain a specific dosage or volume of medication when they are initially provided, as compared to conventional syringes, which are furnished empty and filled by the user before making an injection.
Alternatively, a medical cartridge may be used, such as an ampoule or vial, that includes a penetrable seal instead of a needle on one end of the barrel, and/or a piston rather than a plunger on the other end. Such medical cartridges are generally inserted into an adapter that includes a hollow body configured to hold the cartridge, a plunger to engage and move the piston in the cartridge, and/or a double-ended needle to penetrate the seal and communicate with the interior of the barrel.
Syringe guards have been suggested that include a body within which a syringe may be received, and a shield that is slidable with respect to the body to cover the needle. For example, U.S. Pat. Nos. 6,030,366, 6,159,183, and 6,171,283, assigned to the assignee of the present application, disclose guards that include a body having an open proximal end for inserting a syringe into a cavity within the body. The body includes a plurality of detents for engaging a flange on the syringe to substantially permanently encapsulate the syringe in the body.
The body includes a distal end with an opening through which a needle on the syringe may extend once received in the body. A shield is slidable over the body between retracted and extended positions to expose and cover the needle, respectively. With the shield in the retracted position and the needle exposed, an injection may be made, and then the shield may be manually advanced to the extended position. In the extended position, cooperating detents on the body and shield lock together, thereby preventing reuse of the needle, reducing the risk of accidental needle sticks, and/or facilitating disposal of the syringe.
Such a guard may be provided to a user without a syringe or medical cartridge. The user may insert a syringe into the guard immediately before use, perform an injection, and advance or otherwise activate a shield on the guard. Such user loading, however, involves extra handling of the syringe, and/or may result in improper insertion of the syringe into the guard.
Accordingly, apparatus and methods for assembling medical cartridges into adapters, such as syringes into guards, to provide pre-loaded injection devices ready for use would be considered useful.
The present invention is directed to apparatus and methods for assembling injection devices, including a syringe or other medical cartridge received into an adapter that may or may not include a shield device. More particularly, the present invention is directed to apparatus and methods for assembling syringes into bodies of guard devices including shields for covering needles of the syringes after use.
In accordance with one aspect of the present invention, an apparatus is provided for assembling an injection device including a medical cartridge and an adapter including a body for receiving the medical cartridge in an open end thereof. A pair of first shafts may be disposed adjacent one another, each first shaft including a helical groove therein extending between first and second ends of the first shaft. One or more second shafts, and preferably a pair of second shafts, may be spaced apart a predetermined distance from the pair of first shafts, the first and second shafts extending substantially parallel to a first longitudinal axis. Each second shaft may include a helical groove therein extending between first and second ends of the second shaft.
The helical grooves in the first and second shafts may have corresponding pitches such that the helical grooves define one or more passages, and preferably a plurality of passages, between the first and second shafts. Each passage may define a transverse axis extending transversely to the first longitudinal axis, preferably extending substantially vertically. In an exemplary embodiment, the helical groove in each first shaft may extend clockwise from the first end to the second end of the first shaft, and the helical groove in each second shaft may extend counterclockwise from the first end to the second end of the second shaft. In addition or alternatively, the helical groove in each first shaft may define a first pitch, and the helical groove in each second shaft may define a second pitch that is an integer multiple of the first pitch. In a preferred embodiment, the integer is one such that the second pitch equals the first pitch.
A drive mechanism may be coupled to the shafts for rotating the shafts, preferably such that the passages move from the first ends towards the second ends of the shafts for carrying a medical cartridge in each passage between the first and second ends while maintaining the medical cartridge substantially parallel to the transverse axis. In one embodiment, the drive mechanism may include a servomotor coupled to each of the shafts, and/or a controller for synchronizing rotation of the shafts.
In addition, the apparatus may include a track adjacent the first ends of the shafts. The track may include a slot, e.g., between two rails, for guiding medical cartridges into the one or more passages at the first ends of the shafts. The track may be inclined downwardly towards the first ends of the shafts, whereby a medical cartridge carried in the slot may slide automatically into a passage appearing at the first ends of the shafts.
In addition, the apparatus may include a carrier defining a second longitudinal axis that intersects the first longitudinal axis at a convergence region. The carrier may include a plurality of pockets spaced apart a predetermined distance corresponding to an axial spacing of the passages defined by the first and second shafts. In one embodiment, each pocket may be formed in a manifold connected to an endless loop that may extend around and between a plurality of wheels, thereby defining an orbital path. Each pocket is configured for carrying a cartridge adapter therein such that the adapter extends substantially parallel to the transverse axis. Preferably, the second longitudinal axis may be substantially horizontal, and the first longitudinal axis may overlie the second longitudinal axis, thereby defining a vertical angle with the second longitudinal axis that is greater than zero degrees.
A controller may be coupled to the carrier, e.g., to a motor driving the endless loop, for controlling movement of the carrier such that each passage overlies a corresponding pocket as the passage and corresponding pocket approach the convergence region.
In accordance with another aspect of the present invention, a method is provided for assembling an injection device using an assembly apparatus including a plurality of shafts spaced apart from one another and including axes that extend substantially parallel to a first longitudinal axis, such as the apparatus described above. The shafts include helical grooves therein such that the shafts define passages extending transversely with respect to the first longitudinal axis between the first longitudinal axis.
The shafts may be rotated about the their axes such that the passages move along the first longitudinal between first and second ends of the shafts. Syringes or other medical cartridges may be directed in a substantially vertical orientation towards the first ends of the shafts, whereby the syringes may be carried by successive passages from the first ends towards the second ends of the shafts while maintaining the syringes substantially parallel to the transverse axis. Simultaneously, guards or other adapters may be carried along a second longitudinal axis that converges with the first longitudinal axis at a convergence region. The guards may be disposed substantially parallel to the transverse axis and spaced apart such that the guards are aligned with corresponding syringes.
As the syringes and guards move into the convergence region, the syringes may be received in corresponding guards. The syringes may be released from the passages at the second ends of the shafts, whereupon the syringes may drop any remaining distance into the corresponding guards. If necessary, a force may be applied between the syringes and the corresponding guards to engage the syringes with detents on the corresponding guards, and thereby secure the syringes within the corresponding guards.
Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.